Lost all my Important photos on ipad mini2 ver 11.2.6

Dears,

I am in a big trouble as I lost all my precious pictures on my ipad mini2

Note :THE IPAD mini WAS NEVER SYNCHED/CONNECTED to Icloud or PC and there was no backup anywhere.

Back ground: I purchased a ipad which used to be a demo handset and then it automatically deleted all my pictures taken from the camera.

Now I need a way to extract the pictures from the hardware nand.

I don't know is it worth to purchase some software like "Phone Rescue"

Please help me recover the pics (Please don't mention the icloud or iTunes backup scenario as it is not applicable as the device never connected)